package com.example.asset.common.interceptor;

import cn.hutool.core.util.StrUtil;
import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.exceptions.JWTVerificationException;
import com.example.asset.common.Constants;
import com.example.asset.entity.SysUser;
import com.example.asset.exception.ServiceException;
import com.example.asset.service.SysUserService;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;

public class JwtInterceptor implements HandlerInterceptor {
    @Autowired
    private SysUserService sysUserService;
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
       String token = request.getHeader("token");
       if(!(handler instanceof HandlerMethod)){
           return true;
       }
       // 执行认证
       if (StrUtil.isBlank(token)) {
           throw new ServiceException(Constants.CODE_401, "无token，请重新登录");
       }
       // 获取 token 中的 user id
       String userId;
       try {
           userId = JWT.decode(token).getAudience().get(0);
       } catch (JWTDecodeException j) {
           throw new ServiceException(Constants.CODE_401, "token验证失败，请重新登录");
       }
       // 根据token中的userid查询数据库
       SysUser user = sysUserService.getById(userId);
       if (user == null) {
           throw new ServiceException(Constants.CODE_401, "用户不存在，请重新登录");
       }
       // 用户密码加签验证 token
       JWTVerifier jwtVerifier = JWT.require(Algorithm.HMAC256(user.getPassword())).build();
       try {
           jwtVerifier.verify(token); // 验证token
       } catch (JWTVerificationException e) {
           throw new ServiceException(Constants.CODE_401, "token验证失败，请重新登录");
       }
        return true;
    }
}